Gas burner



D. L. GETZ ET AL Aug. 2l, 1956 GAS BURNER Filed oct. 23, 195o 2 Sheets-Sheet l DELMoND L. GETz Q ROBERT O. HEDGES ATTO R N EYS WMM/M Aug 21, l956 D.N L. GETz ETAL 2,759,533

GAS BURNER 4Filed Oct. 23, 1950 2 Sheets-Sheet 2 l Llll m1- y Y 7\ l A a4 919s '052e Eig-12 SECONDARY AIR I GAS ND 107y 1Z0 9 PRIMARY AIR y 3mm/m 770 SECONDARY AxR TJ l x5 V w United States Patent GAS BURNER Delmond L. Getz and Robert O. Hedges, Springfield, Ohio, assgnors, by mesne assignments, to Kelsey-Hayes Wheel Company, Detroit, Mich., a corporation of Delaware Application October 23, 1950, Serial No. 191,594

2 Claims. (Cl. 158-110) This invention relates to gas burners, and more particularly to gas burners for conversion use in installations such as furnaces and boilers.

One of the principal objects of the invention is to provide a gas conversion burner which is simple and economical to construct and install, which will operate effectively and eiciently as a conversion burner in a furnace or boiler originally designed for coal tiring, and particularly to provide such a gas burner which will operate with minimum noise of the type usually associated either with the mixing of the gas and primary air or with control of the ame pattern.

It is accordingly another object of the invention to provide a gas conversion burner having a combustion head of such construction and operating characteristics as to provide a fan-shaped flame without requiring the use of refractory hearths or spreader baffles of ceramic or metallic construction in the path of the flame which commonly contribute to flame noise and rumble as a result of the impingement of the flame thereon.

These characteristics are obtained in accordance with the invention by means of a combustion head which effects sandwiching of the initial mixture of gas and primary air between two layers of secondary air as the mixture is discharged from the combustion head. This effect is obtained by discharging the primary air in a generally at annular spray to give a circular fan-like llame pattern, with the secondary air being discharged in similar flat sprays immediately adjacent both sides of the mixed spray, and the secondary air sprays act to spread the ame toward the side walls of the furnace or boiler to give the desired fan-shaped flame without the use of refractory hearths or spreader baffles.

It is accordingly an object of the invention to provide a combustion head for a gas conversion burner having a plurality of discharge orifices or slots arranged circumferentially thereof for discharge around substantially the entire circumference of the combustion head and adapted to be supplied with gas and air in such manner as to discharge a mixture of gas and primary air through the central slot and to discharge secondary air through the outer slots on either side of the gas and primary air mixture in fan-shaped pattern.

It is also an object of the invention to provide a gas conversion burner having a primary air damper and venturi tube combination for admitting gas and primary air to the combustion head which is so constructed as to produce a gradually changing air opening of maximum cross-section for a given area for admitting the primary air in all settings thereof and thus to accomplish initial mixing of the gas and primary air with minimum noise.

Other objects of the invention will be apparent from the following description, the accompanying drawings and the appended claims.

In the drawings:

Fig. 1 is a view in vertical section showing a gas conversion burner in accordance with the invention, the view being generally in section on the line 1 1 of Fig. 2;

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Fig. 2 is a view of the burner taken partly in plan and partly in section on the line 2 2 of Fig. l, with additional portions of the casing broken away to illustrate details of internal construction;

Fig. 3 is a rear view of the burner with the casing broken away;

Fig. 4 is an enlarged fragmentary View of the secondary air damper adjusting mechanism;

Fig. 5 is a fragmentary section on the line 5 5 of Fig. 4;

Fig. 6 is an enlarged fragmentary section on the line 6 6 of Fig. 7 showing the primary air damper and venturi tube;

Fig. 7 is a section on the line 7 7 of Fig. 6;

Fig. 8 is an enlarged sectional view through the combustion head;

Fig. 9 is a fragmentary view in perspective showing one of the lugs on the inner casing of the mixing chamber for receiving locking clips on the mixing casing cover;

Fig. 10 is a detail View in perspective showing one of the locking clips on the mixing casing cover;

Fig. 11 is a fragmentary view in perspective showing one of the lugs for supporting the outer casing of the mixing chamber on the wind box; and

Fig. 12 is a diagrammatic View illustrating the operation of the combustion head.

Referring to the drawings, which illustrate a preferred embodiment of the invention, the control housing 13 is provided with a cover 14 hinged thereto at 15 and having handle knobs 16. The ends 17 of the control cabinet are provided with louvers 18 for admitting air to the interior of the cabinet for transmission through the slide 20 to the secondary air wind box 21 in which is mounted the combustion head indicated generally at 22. The wind box 21 includes a bottom plate 24, a top plate 25 and a wrapper 26 around the end thereof, and the connection between the wind box and slide is axially adjustable to lit different installation conditions. Legs 27 are adjustably mounted at 28 in the control cabinet and wind box for properly positioning the combustion head with respect to the original grate line of the furnace or boiler.

The cabinet 13 is provided with an enlarged opening 30 for admitting secondary air to the slide and wind box, and this opening is controlled by an adjustable secondary air damper 31 hinged to the cabinet by means of brackets or tabs 32. A curved adjusting guide 33 of sheet metal for the damper 31 is welded or otherwise secured at 34 to the bottom of the slide 20 and is provided with an arcuate slot 35. The guide 33 passes through a slot 36 in damper 31, and a bracket 37 on the damper has a nut 38 welded thereto to receive a lock screw 40 for releasably securing the damper in fixed relation with guide 33 to hold it in adjusted position in accordance with the desired eiective opening for secondary air.

The gas pipe 44 for connection to the main supply line leads to the control manifold comprising gas valve 45 and pressure regulator 46, the gas valve being operated by the room thermostat or by the pilotstat 47 and safety pilot 50 in the usual way. Tlhe pilot 50 is shown as mounted in the wind box 21 by means of a bracket 51 and is provided with a supply tube 52 and vent tubes 53 supported in the control cabinet by a bracket 55.

From the control manifold, the gas passes through the gas manifold 59 to the gas spud 60, which is shown in detail in Figs. 6 and 7 and is supported within the slide 20 by a bracket 61 having a generally U-shape in side elevation. The spud 60 is provided with a large bore 62 at its entering end which narrows at 63 to a discharge orifice 65 of restricted dimensions. The spud cooperates with the belled end 66 of a tube 70 to form a venturi combination for mixing primary air with the gas. The tube70 includes a cylindrical portion 71 slidable for adjustment within the primary air tube 72 leading to the combustion head 22, and a clamp 73 is brazed to tube 70 forattachment to'v the Spud brack'e't 51 t' I 'n-itain? the belled end 66 in fixed relation with the dise'h'al'g'e 'end' di the 'Spud defining-an untsstructed niiet passage 75 fdr primary air to the tube '70.

The" admission' i prima-ry air t6 this veint'r'i arrange ment is controlled by a conical damper 77 having' hub' portion` 78 slidable on the gas Spud 60. A bracket" 79 is secured to the hub 7 3 andA is slotted at its upper eridfo'r connection to' an adjusting screw su threaded inf-h upper end portion of the spud bracket 61. A control rod 81 is secured to the rearward e'nd of the screw' 801 andg extends intofthe interior of the control cabinet' where it is supported in bearing S2 having a lock screw 33". t A con# trol knob 8S provides for convenient rotation of rod S1 when thelock screw 83is' released.

In operation, the gas transmitted under pressure tothe spud is discharged at high velocity' thro'ug'h therestricted orifice into the tube' 711. The velocity of the' gas passing into this tube draws primary air into the tube through the inlet passage '75 for mixture with the' gas: inside-tube 7i) and transmission to the' combustion he'ad.

The amount of primaryl air drawn into the venturi tube 70A iiow area which has been found to etect the desiredA ad#A mission and mixing of air with the gas with niinirnum noise.

The structure and operation of the combustion headl 22 is` shown in: detail in Figs, 8 to l2. The annular mixing chamber for the gas and primary air" is defined by an outer casing` 91 and an inner casing 92, the outercasing 91 being adapted at 93 for direct connectionV with the air tube 72. The casing 91 is supported on an' upstanding collar portion 95 onl the top 25 of the wind box and de-V firies therewith an annular chamber 96 for receiving secondary air from the inside' of the wind box:

The casing 91 has the peripheralV lip'portion 99 at its upper end supported in spaced relation with the upper end of the collar 95vto dene therewith a substantially continuous annular discharge orice or slot from the chamber 96 extending circumferentially about lthe combustion head. Referring to Figs. 8 and' 11, the lip portion 99A on casing 91 is provided with a plurality of lugs 101'onK theunderside thereof, and these lugs are ,cut out at 102 toiit the upper end of the collar 9S, thus defining the slotY 100 between the underside of lip 99 and the'uppe rim of collar' 9S. At its lower end, the casing 91 includes a cross" br 105 secured by aboltand nut106 to abracket107 welded or otherwise secured to the bottom 24 of the W'il'idfbX. A

The inner casing 92 of the mixing chamber` also includes a circumferential lip 1419 which is supported in spaced relation with the lip 99 to form a circumferential dis-V cliargeo'rifice or' slot 11) for t-he mixed gas Vand primary air from the mixing chamber 90. The casing is generally of inverted bell-shape, with its lower end'- 111 being fitted within the cylindrical boss portion 112 atthe lower part of casing' 91'. On the upper surfaceV of the lip. portion' of casing 91 are a plurality of upstandinglug's 113 whioli engage the underside of the lip` 109and thus maintain' itin desired spaced relation'aboveV the lip 99 to define therewith the discharge slet ite. Tlius with the lip '99 flared upwardly as shown and terminating in a flat land i114;- rhe mixed gas and lair freni chamber' no is' discharged' Athrough slot 119 iu a substantially fiatA annularI spray arranged in a faii-like pattern circumfe'retially' of the'jrclotnbustion head. i

The casing 92 forms a central chamber 1215 for receiv# ing secondary air from the wind box, and itis provided witirstepeover it supp/erred iii such mnner as to' denne with the lip 109 a substantially continuous annular discharge orifice or slot for the secondary air from the chamber 115. The lip 109 is provided with a plurality of upstanding lugs 121 on its periphery which have tapered upper surfaces 122 for receiving the downwardly sloping rim portion of the cover 119 to support the cover in the desired spaced relation with lip 109 to define the slot 120.

In order to secure the cover 119 removably on casing 92, each of the lugs 121 is provided with a slot 123 on its innerl side for locking engagement with one of the' locking clips 12S on' the cover 119. As shown in Fig. 10, thev clip 12S is generally Z-shaped and includes a lower flange which has an upwarly sloping portion 126 and a fiat portiony 127 terminating in an upstanding tab 128. Thus when the cover 119 is se't on the casing 92 and rotated in clockwise direction as' viewed from above, the ange portion 126 on each clip will slide into slot 123 on one of the lugs 121 until it frictionally engages the overhangin-g portion of this slot to lock the slot in place,4 the rotation of the cover being limited by engagement of the tabs 128 with the sides of the lugs 1211.

In' operation, the mixture of gas and primary air ignited by the pilot 50 is discharged from the :slot 100 in a substantially flat fan-shaped iiame around the entire circumference of the combustion head. At the same time, the air is drawn through damper opening Stiby natural draft action into slide Ztl, and while some of this air is sucked into venturi tube 79 as primary air, the remainder Hows into the chambers 96 and 115 and is discharged through the slots 100 and 126 as initially fiat annular sprays immediately below and above the iiarne which intermix with the ame to provide the proper amount of air for complete`r combustion. ln addition, the action of these two 'air ring's together with the velocity discharge of the gas ame from the intermediate `slot 11@ produces the desired overall fan-shaped pattern for the flame and causes it to spread to the side walls of the furnace or boiler without the aid of refractory hearths, spreader bafiies or other flame directing members. y

It will also be Iseen that this burner construction is easily adaptable to varied installation conditions without altering its operating characteristics. The sliding connection between the slide 2t? and the wind box make it possible to vary the position of the control cabinet as required for a particularinstallation,- and the adjustable legs are similarly `of assistance in fitting the burner in proper relation with a particular furnace or boiler. Also, with the gas spud and venturi tube 'l'timounted in the desired fixed relation by means of the common mounting bracket 61.

and withnthe other end of the venturi tube slidable in the air tube 72, a similarly adjustable connection is provided without affecting the proper operating relationship of the spud andthe belled end portion of the venturi tube.

While the form of apparatus herein described constitutes a preferred embodiment of the invention,l it is to be understood that the invention is'not limited to this precise form of apparatus, and that changes may be made therein withioutrdeparting from the scope of the invention which is defined in the appended claims.

What is claimed is:

l. A gas burner combustion head` for delivering a subistantially fiat fan-shaped fiame establishing evenlyA distributed heatin'g of a combustion chamber free of external flame spreading means, comprising a secondary air wind box, a pair of inner and outer annular casings `arranged in telesc'oped relation to form a central chamber and a surrounding'annularv chamber, means supporting said casings in substantially vertical position partially within and eX- tending abo'vosaid wind box, means within said wind box for connecting said annular chamber toV a source of mixed gas andl primary'air, circumferential lips-on said casings pjectiigV substantially radially therefrom in vertically spaced relation over a substantial distance beyond said outer casing and of substantially the same diameter and forming'a'crr'esponding circumferential discharge passage o'f .substantial radial 'extent' from said annular chamber to cause said gas-air mixture to be discharged in a .flat fanshaped pattern, a cover plate for said inner'casmg supported in vertically spaced relation with said inner casing lip, said cover being of substantially the same dlameteras said inner casing lip to denne therewith a circumferential discharge slot for discharging secondary air radially from said central chamber above said discharging gas-alr mlxtue to maintain Isaid discharging gas-air mixture in said at fan-shaped pattern, a collar on the top of said wind box including a tubular portion lsurrcmnding and of greater diameter than said outer casing and of lesser diameter than said lip on said outer casing to form with said outer casmg a further annular chamber for secondary air, means maintaining said outer casing 1ip and the upper periphery of said collar in vertically spaced relation to form an additional circumferential slot for substantially radial discharge of secondary air below said discharging gas-a1r mixture, and means separately connecting the interiors of said co'llar and said inner casing with the interior of said wind box to supply secondary air thereto for discharge through said air discharge slots.

2. A gas burner combustion head for delivering a substantially at fan-shaped flame establishing evenly distributed heating of a combustion chamber free of external flame spreading means, comprising a secondary air wind box, a generally cup-shaped main casing having a tubular opening in the bottom thereof, means supporting said main casing with the lower end thereof within said wind box, an inner casing having the lower end thereof mounted in said tubular opening and extending vertically within said main casing to define therewith a central chamber and an annular chamber, means for supplying a mixture of gas and primary air to said annular chamber, circumferential lips of substantially the same diameter projecting radially from both of said casings in vertically spaced and overlying relation to form a discharge slot from said annular chamber of correspondingly substantial radial extent causing said gas-air mixture to be discharged therefrom in a flat fan-shaped pattern, said inner casing being open at the lower end thereof to receive secondary air from said wind box, a cover on the upper end of lsaid inner casing Isupported in vertically spaced relation with said lip on said inner casing to dene therewith a circumferential discharge slot for said secondary air, said cover being of substantially the same diameter as `said lips to cause said secondary air to be discharged radially above said discharging gas-air Imixture to maintain said discharging mixture in said flat fan-shaped pattern, a tubular collar of greater diameter than said main casing extending upwardly from the top of said wind box and opening at the lower end thereof into said wind box to receive secondary air directly therefrom, said collar being of lesser diameter than said lip on said main casing, and means maintaining said lip and the top of said collar in vertically spaced relation to form an additional circumferential discharge slot for primarily radial dlscharge of secondary air below ysaid discharging gas-air mrxture.

References Cited in the file of this patent UNITED STATES PATENTS 470,862 Clark Mar. 15, 1892 1,956,857 Cunningham May l, 1934 2,269,333 Bloom Jan. 6, 1942 2,275,555 Power Mar. 10, 1942 2,467,626 Norman Apr. 19, 1949 2,560,184 Norman July l0, 1951 2,625,215 Hart et al Jan. 13, 1953 FOREIGN PATENTS 171,424 Great Britain Nov. 21, 1921 217,771 Great Britain June'26, 1924 

